x86/paravirt, objtool: Annotate indirect calls

Paravirt emits indirect calls which get flagged by objtool retpoline
checks, annotate it away because all these indirect calls will be
patched out before we start userspace.

This patching happens through alternative_instructions() ->
apply_paravirt() -> pv_init_ops.patch() which will eventually end up
in paravirt_patch_default(). This function _will_ write direct
alternatives.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 554841fab717aef09d2b5cc57410a6eed8c2df0c..c83a2f418cea097bb2c5a9545409c5e6efcbbc50 100644 (file)
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -7,6 +7,7 @@
 #ifdef CONFIG_PARAVIRT
 #include <asm/pgtable_types.h>
 #include <asm/asm.h>
+#include <asm/nospec-branch.h>
 
 #include <asm/paravirt_types.h>
 
@@ -879,23 +880,27 @@ extern void default_banner(void);
 
 #define INTERRUPT_RETURN                                               \
        PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_iret), CLBR_NONE,       \
-                 jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_iret))
+                 ANNOTATE_RETPOLINE_SAFE;                                      \
+                 jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_iret);)
 
 #define DISABLE_INTERRUPTS(clobbers)                                   \
        PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_irq_disable), clobbers, \
                  PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE);            \
+                 ANNOTATE_RETPOLINE_SAFE;                                      \
                  call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_disable);    \
                  PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
 
 #define ENABLE_INTERRUPTS(clobbers)                                    \
        PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_irq_enable), clobbers,  \
                  PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE);            \
+                 ANNOTATE_RETPOLINE_SAFE;                                      \
                  call PARA_INDIRECT(pv_irq_ops+PV_IRQ_irq_enable);     \
                  PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
 
 #ifdef CONFIG_X86_32
 #define GET_CR0_INTO_EAX                               \
        push %ecx; push %edx;                           \
+       ANNOTATE_RETPOLINE_SAFE;                                \
        call PARA_INDIRECT(pv_cpu_ops+PV_CPU_read_cr0); \
        pop %edx; pop %ecx
 #else  /* !CONFIG_X86_32 */
@@ -917,21 +922,25 @@ extern void default_banner(void);
  */
 #define SWAPGS                                                         \
        PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_swapgs), CLBR_NONE,     \
-                 call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs)          \
+                 ANNOTATE_RETPOLINE_SAFE;                                      \
+                 call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs);         \
                 )
 
 #define GET_CR2_INTO_RAX                               \
-       call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)
+       ANNOTATE_RETPOLINE_SAFE;                                \
+       call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2);
 
 #define USERGS_SYSRET64                                                        \
        PARA_SITE(PARA_PATCH(pv_cpu_ops, PV_CPU_usergs_sysret64),       \
                  CLBR_NONE,                                            \
-                 jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret64))
+                 ANNOTATE_RETPOLINE_SAFE;                                      \
+                 jmp PARA_INDIRECT(pv_cpu_ops+PV_CPU_usergs_sysret64);)
 
 #ifdef CONFIG_DEBUG_ENTRY
 #define SAVE_FLAGS(clobbers)                                        \
        PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_save_fl), clobbers, \
                  PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE);        \
+                 ANNOTATE_RETPOLINE_SAFE;                                  \
                  call PARA_INDIRECT(pv_irq_ops+PV_IRQ_save_fl);    \
                  PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)
 #endif

diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index f624f1f10316c248911585f757ea5bd257e98434..180bc0bff0fbd98195b8e81ce9aa7232dde06ee2 100644 (file)
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -43,6 +43,7 @@
 #include <asm/desc_defs.h>
 #include <asm/kmap_types.h>
 #include <asm/pgtable_types.h>
+#include <asm/nospec-branch.h>
 
 struct page;
 struct thread_struct;
@@ -392,7 +393,9 @@ int paravirt_disable_iospace(void);
  * offset into the paravirt_patch_template structure, and can therefore be
  * freely converted back into a structure offset.
  */
-#define PARAVIRT_CALL  "call *%c[paravirt_opptr];"
+#define PARAVIRT_CALL                                  \
+       ANNOTATE_RETPOLINE_SAFE                         \
+       "call *%c[paravirt_opptr];"
 
 /*
  * These macros are intended to wrap calls through one of the paravirt